4. There are student Ling † Ren who need accommodation. If each room houses 4 people, then there are still 20 people without accommodation; if each room houses 8 people, then there is one room that is neither empty nor full. Therefore, the number of dormitory rooms is rooms, and the number of students is people.
Solution
.
Let the number of dormitories be , and the number of students be (both are integers). Then
\left\{\begin{array} { l }
{ y - 2 0 5 .
\end{array}\right.\right.
Therefore, .
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